Gun sight



July 30, 1946. J. D. TEAR ET Al.

GUN SIGHT Filed Nov. 2, 1940 INVENTRS JAMES DTEAR CHARLES W. BUCKLEY BY ,QU/QMM.,

ATTORNEY Patented July 30, 1946 UNITED STATES PATENT OFFICE GUN SIGHT Application November 2, 1940, Serial No. 363,956

8 Claims. 1

This invention relates to that class of automatic gun sights in which the bearing rate is combined with a function of range to introduce the proper settingof the sight with respect to the gun, that is, the angle of deection.

In an application of James D. Tear, Serial No. 358,246, filed September 25, 1940, covering Gun sights, there is shown a sight mechanism of this type, a characteristic of which is the fact that when an alteration in bearing rate is made by the operator. the sight moves i'lrst in relation to the gun in a direction to bring the sight towards the target, and then the sight moves in the opposite direction until the proper deilection angle is obtained for the bearing rate set up.

. With sights of this type in order to bring the Ysight and with it the gun back on the target an over-correction in the rate of train must be set up by the operator and maintained until the sight comes on the target. One of the objects of this invention is the provision of means for automatically introducing and eventually eliminating that excess rate.

Another object of the invention is to provide in such a gun sight a wider range of rate of train of the gun and sight for more readily bringing the sight on the target than has heretofore been known.

Other objects will be apparent from a consideration of the specication and the drawing in which the single figure is an isometric View of one embodiment of the invention.

In the present invention means actuated by the rate control member are provided for generating an over-correction to the rate or an excess rate and this excess rate is translated into an increment of bearing and applied to the training of the gun. Specically in the preferred embodiment, the rate member of a variable speed device which trains the gun in azimuth is not connected solely and directly to the train rate control handle, as has been the practice heretofore, but is connected to the output of a dilerential, one of the inputs of which is a shaft turned directly by the train rate control handle and the Other input of which is a shaft turned by the train rate control handle through a separate train of gears. By this arrangement the temporary over-correction to the rate of train necessary to bring the sight on the target is automatically set up in the training device.

The over-correction in rate so introduced is promptly eliminated by the reverse movement of the said other input, which is effected by the re.- storing or neutralizing action of a delayed follow-up or relay mechanism. In the disclosed embodiment of the invention, the delayed followup or relay mechanism is the mechanism the output of which is connected to the sight to move it in a direction opposite to that in which the sight was lirst moved by the rate control handle as will be explained hereinafter.

In this disclosure a multiplier, which converts the movement of the rate control handle to a change in deflection, is connected between the rate control handle and the relay mechanism, but it is obvious that the multiplier could be placed in other positions such as next to the sight, as shown in the reference application. When placed as in this embodiment, corrections to sight deection due to changes in range settings will introduce a compensatory increment in the train angle of the base and hence will not displace the sight from the target.

Referring to the drawing. I represents a base adapted to angular movement about its axis. On base I is mounted gun 2 on trunnions 3 and brackets 4. Sight 5 is mounted on trunnions 6 and bushing 1, which is free to turn on stud 8 mounted on base I.

On the base I is mounted a variable speed device 9 whose output, shaft I0, is connected by gears II to shaft I2 on the end of which is pinion I3 which meshes with teeth I 4 of a fixed ring gear surrounding the base I. Bracket I5 on base I forms a bearing for shaft I2.

The driving plate I6 of variable speed device 9 is driven through worm Il and shaft I8, which is the output of variable speed device I9. The driving plate of variable speed device I9 receives its power from motor M through worm 2| and the teeth in the edge of plate 20. The output of variable speed device I9 will be proportional to the distance of the rate member or ball carriage 22 from the axis of plate 20. The ball carriage 22 is moved by links 23 and 24, the latter being pivoted on bracket 25 mounted on base I.

In order that plate I6 of variable speed device 9 may be driven normally at a predetermined and minimum speed, a stop 2S in the form of a bracket is mounted on base I and is of such length that its free end will engage ball carriage 22 when the ball carriage is at the proper distance from the axis of plate 20. Ball carriage 22 is kept in engagement with stop 26 by the action of spring 2l, which is attached to link 24 and stop 26, except when a force is applied to slewing control handle 2B to move link 24 to the left.

The rate of train control handle 29 is pivoted on bracket 30 mounted on base I. Handle 29 is amaca? connected to a racked control member Sila, which is connected to sight by shaft S I differential 32, shaft 33, Worm 34, arm 35, and bushing 7. Shaft 3i is also connected to one input of multiplier 36 by shafts 3l and 33. The other input to multiplier 36 is shaft 39, Which is turned by crank 4I) in accordance with a function of the range. The output of multiplier 36, shaft 4I, is connected to the rate member 42 of variable speed device 43 through differential 44 and shaft 45. The output of variablerspeed device 43 is shaft 4S, Which iS COImBCt/d to one side of differential 32, the other side of the differential being shaft IJ, as previously described. Shaft 45 is also connected to differential 44 by shaft 47.

The rate member 48 of variable speed device 9 is connected to the output of differential 43, the inputs of Which are shaft 37 and shaft 50, the latter being connected to shaft 45 through gears 5I and 52. Y

A Operation Assuming that the apparatusvis in its neutral or secured position, as shown in the drawing, and it is desired to train the gun and sight on a target, say to the right, rate control handle 29 is pointed to the right, moving rate member 48 and the ball carriage of variable speed device SI through control member 32a, shafts 3l and3I and differential 4S. In this manner the turning of the base I to the right is controlled. If it is desired to turn the base I around quickly, handle 28 is pointed tov the left movingV control member or link 23 and the ratemember or ball carriage 22 totheV left, thus increasing the vrate of output of variable speed device I9 and the rate of movement of plate It. Control handle 23 may conveniently be arranged as a foot treadle, thus leaving the hands of the gunner freefor other operations While swinging the base I around, such as setting the' range into multiplier When the sight ofthe gun approaches the target, the slewing control handle23 is released and control member 23 and its ball carriage are pulled to the right under the actionjof spring 27 until the ball carriage comes up against stop 2S, when the variable speed device operates to produce the predetermined rat-e of turning of plate IS. Handle 29 is pointedv to the right or left to adjust the rate of train of base I so that sight 5 follows the target. In this condition the rate of train, as representedfby the position of shaft 3i, has been set into the trainingdevice by the movement of rate member 48 to la corre-v sponding distance from its mid-position andthe rate of train has been multiplied by the time of iiight of the projectile by the multiplier 3S and the product of the multiplication has been transmitted to the sight through variable speed Ydevice 43, shaft 4S, differential 32, and shaft 33. With no further movement of handle 29, control element or rate member 42 of variable speed device 43 is in its neutral position, having been brought there by the follow-up action of shaft 4I connected to shaft 45 through differential 44. As shaft 45 is in its mid-position, so also is shaft 52. The operation of shaft 53, connected to shaft 45 by gears 5I and 52, will be explained hereinafter.

The ratio of transmission between the control member 38a and shaft 33 through shaft 3I and differential 32 is selected as (k) and the ratio of the gearing between the control member 33a and shaft 33 through the variable speed device 43 is (t-l-lc) where t is the time of flight factor in` rtroduced into the system by the multiplier 36.

To illustrate the operation of the apparatus to effect a change in rate of train and set upa change in deflection, it is assumed that the target is moving to the right and the rate of train (dB), represented by the position of shaft 31, is underset, that is, the sight is lagging behind the target both in rate and in distance and a higher rate of train (dB) and therefore a greater deflection are required and an excess rate of train must be temporarily introduced to overcome the distance that the sight lags behind the target.

The operator points handle 29 further to the right. He thereby turns the center of the differential VS2 through -lc (dB-dB) This causes a turning of the shaft 33 and hence a movement of the sight to the right or toward the target. Coincidently the shaft 3'I which is geared to shaft SI turns shaft 38 Whichis one of the inputs to multiplier 3E. Shaft 4I, the output of multiplier 36, is moved in proportion t0 the increase in rate of train multiplied by the constant 1c plus the time of night, or (lc-ift) (dB-dB), Where' t is the time ofl flight as set into multiplier 36 by crank 4U. Shaft 4I being connected toshaft 45 through differential 44 moves the rate member 42 of variable speed device 43.V The actuation of the output shaft 46 of this variable speed device is thus initiated and continues until the rate member 42 is returnedto its zero position through shaft 47 and differential yI4 in the usual manner of such follow-up devices; v The total movement of the shaft 46- and hence of the side of vthe differential 32 to Which` it is connected is of the value (7H-t) (dB'-dB). This therefore operates to neutralize the quantity lo (dE-03E) set into the differential 32 by shaftr SI, and additionally to effect a positive output of differential 32 equal to t (dB-dB). Due to the mechanical time lag which is inherent Vin followup mechanisms of this type, the neutralizing of the quantity 7c (dB'-dB) lagsv behind its introduction into the differential 32 and hence the shaft 33 is first turned to move the sight towardthe target, as above stated, and. then is reversedy and actuated to give to the sight the correct deflection angle for the new rate of train. In` other Words the final change in the setting of the shaft 3S is t(dB-cZB) At `the' same time that. shaft 4.5i is moved. to change the position of rate member 42 of variable speed device 43, shaft 45 moves. shaft 5I! through gears 5I and 52. The movement ofshaftl 5@ is combined with that of shaft 31 by differential 49, so that the rate member 48 is moved directly in accordanceA with the increase in the train-ing rate (dB*dB)' and also is moved an additional amount due to the movement of shaft 5I] by shaft 45 `Aand the gears 5I and 52. This addi'- tional movement of member 4B is neutralized by the Vfollow-up action of shaft 41 and differential '44, so that when the rate member 42 is being moved to its mid-position, the additional or ex-V sponding temporary excess training rate of base- I will automatically'train the base` I such an amount that it is not necessary for the opera;V

torto over-correct the rate of ,train by the handie zo to overcome the distante that the sightl had lagged behind the target when the operator introduced the higher rate of train and, ii the new train rate is correct, the sight will be on the target when the new deflection is set up and the sight will remain on the target.

` The invention is shown as applied to the training of a gun and the deflection of the associated sight, but it is apparent and intended that the invention shall be applied to other movements of the gun, such as elevation. It is also contemplated that various dials may be applied to the mechanism for indicating the instantaneous values represented by different parts of the mechanism as desired.

It isfevdentfthat various changes may be made in the form, construction and arrangement of thevarious parts of the mechanism without departing from the spirit of the invention as defined in the appended claims. For example it will be understood that the temporary additional rate movement generated by the drive branching from the direct drive to the rate member of the variable speed device may be otherwise translated into an increment of train movement of the base. It will also be understood that other types of variable speed devices may be used, such as hydraulic or electric, or a gyroscope acting under a precessing force proportional to the movement of the rate control handle.

We claim:

1. In combination, an angularly movable base, a gun mounted on the base for angular movement therewith, a sight mounted on the base and adapted to angular movement relative to the gun, a differential having an output member connected to move the sight, a variable speed device adapted to train the base at a variable rate and including a rate member positionable to control the rate, a second differential having an output member connected to position the rate member, a control handle, means connecting the control handle to input members of the first and the second differentials, a multiplier having inputs settable by the control handle and in accordance with a function of the range, a third differential having an input member connected to the output of the multiplier, a second variable speed device including a second rate member, means connecting the second rate member to an input member of the second diierential and the output member of the third differential, and means connecting the output of the second variable speed device to input members of the first and the third differentials, whereby the delayed follow-up action of the output of the second variable speed device moves .i

the sight in a direction opposite to and in an amount greater than that caused directly by movement of the control handle and moves the rate member of the rst variable speed device in a direction opposite to and in amount equal to that caused by movement of the control handle as applied through the multiplier.

2. In combination, a variable speed device including an output member and an adjustable rate member for varying the rate of movement of the output member, a control member, means for positioning the rate member in accordance with the position of the control member, means actuated by changes in position of the control member for temporarily modifying the position of the rate member, a second control member, and means actuated by said second control member to increase the effect of the rst control member in varying the rate of movement of the output member.

3. In combination, an angularly movable base, a variable speed drive including an output member connected to angularly move the base at a variable rate and a rate member movable to vary the rate, a movable control member, means for positioning the rate member directly in accordance with the position of the control member, a relay actuated in response to movement of the control member, said relay including an element positioned in accordance with the rate of movement of the relay, and means for additionally moving the rate member in accordance with the position of the element.

4. In combination, an angularly movable base,

a variable speed driveincluding anoutput mem-Y ber connected to angularly move the base at a varablerate and a rate member adapted to vary the rate in accordance with its position, a movable control member, means for initially positioning the rate member directly in accordance with the position of the control member, means for modifying the position of the rate member in accordance with the movement of the control member, and a delayed action relay actuated by movement of the control member for restoring the rate member to its initial position.

5. In combination, an angularly movable base, a gun mounted on the base for angular movement therewith, a variable speed drive including an output member connected to angularly move the base at a Variable rate and a rate member adapted to vary the rate in accordance with its position, a sight mounted on the base for' angular movement relative to the gun, a movable control member, means for positioning the rate member directly in accordance with the position of the control member, means for initially moving the sight in one direction in accordance with the movement of the control member, means actuated by movement of the control member for introducing additional movement into the rate member, a delayed action relay actuated in response to movement of the control member, means actuated by the relay for removing the additional movement of the rate member, and means actuated by the relay to move the sight in a direction opposite to its initial movement.

6. In combination, an angularly movable base, a gun mounted on the base for angular movement therewith, a variable speed drive having a driving member, a rate member and a. driven member, means connecting the driven member to angularly move the base, a sight mounted on the base for angular movement relative to the gun, a movable control member, means for positioning the rate member directly in accordance with the position of the control member, means for initially moving the sight in one direction in accordance with the movement of the control member, means actuated by movement of the control member for introducing additional movement into the rate member, a delayed action relay actuated in response to movement of the control member, means actuated by the relay for removing the additional movement of the rate member, means actuated by the relay t0 move the sight in a direction opposite to its initial movement, a second variable speed drive including a driven member, and means connecting the driven member of the second variable speed drive to the driving member of the rst mentioned variable speed drive.

`7. In combination, a variable speed device including an input member, an output member and a positionable rate member for varying the ratio 7. of movement between the input member and the; output member. econ-trol membert. means for positioning the rate member directly in accord--A ance. with the. position of; the control member, means actuated by change. in position of the control member for modifying thel position ofy the rate member temporarily,y a second variable speed device including an input member, an out put, member and,v a postionable rate, member for varying the ratio of movement between the input member and the output member, power means for driving the input member of the second variable speed device, driving means connecting theoutput member of the. secondY variableA speed device tov the input member of the first. mentioned variable speedv device, biasing means to` normally position the rate. member of the second variable speed. device at a predetermined position. and a; second sentol member adapted to.V

of the outputl nuernber,y a` control member,l means` for positioning the rate member in accordance with the position of thecontrol. member, a second control member.. and; means actuated by said second control member to increase thevr eiect. of the first, control member in varying the ratel of movementoir the. output. member. Y Y.

lJAMES D. CHARLES W. BUCKLEY., 

